I was talking to a friend about this. She allowed an Uncle she's very close to choose a middle name for her son. He was thrilled and has very traditional tastes and so she wasn't worried about what he'd choose. There was one name though that she really hates but didn't think to tell him about it. Of course he unwittingly chose that name. She didn't have the heart to tell him that she hated it, so put it on the BC.
Have you ever allowed anyone else to choose a name and how did it work out?